POTABLE WATER
TREATMENT

Long-chain PFAS remain in the human body for a long time after ingestion. In animal studies, PFAS substances have been found to impact the liver, to be carcinogenic and to reduce the fertility rate. The usage of these compounds is now strictly regulated.

Specific ion exchange resins can be used for the removal of PFAS from water sources. Typical applications are the removal of PFAS from drinking water, from processing water for food stuff, from groundwater or from wastewater.

CHEMRA offers nitrate selective resins like TREVERLITE IXA810/Cl and a strong base anionic resin Type 1 like TREVERLITE IXA110/Cl – depending on the composition of the water to be treated, operating conditions and intended plant size. These anionic resins are supplied in the chloride form and are regenerated with brine.

CHEMRA can provide the necessary technical support and offer solutions to minimize waste generation.

Surface water contains many natural organic compounds, mainly humic acids. These are typically large molecules which can be trapped on specific macroporous strong base anionic resins such as TREVERLITE SCA100, TREVERLITE SCA300 (both styrenic) or TREVERLITE SCA200 (acrylic). These resins work as “scavengers” to remove these acids or to “polish” the water, and can be regenerated with brine. Their high loading capacity allows for long cycles and reduces the overall environmental footprint.

Perchlorates are present in groundwater in many regions at concentrations above the regulated limits (6 ppb in USA, 10 ppb in Europe).

CHEMRA offers different treatment solutions depending on the local regulations. These resins can either be regenerable or “single-use”. They are strong base anionic resins, with hydrophobic surface properties. The residual perchlorate concentrations after treatment can be below 1 ppb.

Boron is naturally present in groundwater and seawater as boric acid B(OH)3. Boron levels cannot exceed the World Health Organization guideline of 0.5 ppm to be considered suitable for human consumption.

CHEMRA provides a simple and economical solution using TREVERLITE CHE750, a chelating resin with N-Methyl-D-glucamine functionality which selectively removes boron even in a high salt background. The regeneration can be performed in co-flow mode in two steps, and is regenerated using dilute acid followed by conversion using caustic soda.

Uranium is a natural radionuclide generally present at trace levels in groundwater. It is typically found as anionic uranyl complexes. In several European regions groundwater exceeds the European guideline of 30 ppb as U (new water directive (EU) 2020/2184).

Strong base anionic resins or medium base anionic resins efficiently remove uranyl complexes with an efficiency of more than 99%. Removal efficiency depends on the concentration of background anions of the raw water. Maximum removal may be constrained by local regulatory limits for the allowable limit of uranium on the resin.

Regeneration is possible, but most applications are “single-use, once through” to avoid the release of concentrated effluent in environment and drinking water. Disposal and transportation of spent resin is subject to local, state and federal regulations.

While trivalent chromium (Cr3+) is not considered as harmful, hexavalent chromium (Cr6+) is a carcinogen and emerging health concern with new European directive targeting a limit of less than 50 ppb today and 25 ppb in 2036. US EPA has fixed the maximum contaminant level (MCL) of total chromium at less than 100 ppb, with California even lower at 50 ppb.

CHEMRA offers TREVERLITE IXA110/Cl, a strong base anionic resin which can remove more than 99% of the chromium from raw water. This resin is regenerable. Operating conditions depend on the water composition and plant layout. CHEMRA can provide technical support and assist with plant design.